1. Field of the Invention
The present invention generally relates to systems for reducing the incidence of complications that occur following many surgical procedures within the chest or abdomen. More particularly, the present invention relates to systems for reducing post-surgical complications that occur due to the natural tendency of the human body to form adhesions between injured areas within body cavities.
2. State of the Art
As a result of the healing processes that follow chest and abdominal surgery, complications frequently arise due to the natural tendency of the human body to form adhesions, which are connecting tissue structures between injured areas within body cavities. Adhesions may form regardless of the nature of surgical procedures, whether done in a so-called minimally invasive fashion using laparoscopy or with a standard technique involving one or more relatively large incisions. A teleological explanation of adhesions is that they serve to limit the spread of infection from incidental stab wounds or perforations of body cavities. Regardless of their teleological purpose, however, these connective tissue bridges may cause various, often serious, complications. Usually the relief of post-surgical complications caused by adhesions requires another surgery. The subsequent surgery is complicated by the adhesions that were formed as a result of the previous surgery. The second surgery, itself, is likely to result in further adhesions and a continuing cycle of additional surgical complications.
One example of a problem that can be caused by adhesions is that, following abdominal surgery, loops of intestine may become entangled or twisted about these adhesions. The entanglements may cause partial or total flow obstruction through the bowel, or may compromise the blood flow to and from the bowel. If such a condition is not relieved rapidly, the bowel dies and shortly thereafter the condition causes death of the afflicted patient. As another example, adhesions that form in the pelvis after obstetric or gynecologic surgery may cause sterility as well as chronic pelvic pain.
Various suggestions have been made to avoid, reduce, or eliminate the formation of adhesions. For instance, standard surgical procedure in the United States often includes the steps of washing powder from surgical gloves prior to surgical operations, using powder-free gloves, and washing body cavities thoroughly prior to closing incisions. Another of the strategies that has been suggested to prevent adhesion formation is to loosely place a non-reactive barrier between an injured peritoneal surface and internal organs. Material such as Interceed(trademark) and Seprafilm(trademark) and methods as described in U.S. Pat. No. 5,791,352 to Reich et al., have been advocated for minimizing adhesions. Such procedures, however, have not been shown to be significantly effective in reducing the formation of adhesions.
It also has been suggested that injured tissue naturally releases many chemical messengersxe2x80x94including transforming growth factorsxe2x80x94which are responsible, at least in part, for peritoneal healing. One of those factors, TGF-xcex2, may stimulate the formation of adhesions. In other words, it has been postulated that, when the integrity of the abdominal lining (either peritoneum or pleura) is breached, the natural response is to release a substance such as TGF-xcex2. Upon release, such substances initiate a healing process including forming connective tissue bridges (i.e., adhesions). To restrict the spread of TGF-xcex2 from injured tissue sitesxe2x80x94and thus, possibly, to inhibit the formation of adhesionsxe2x80x94barrier sheets have been developed. As mentioned above, Interceed(trademark) and Seprafilm(trademark) are examples of such barrier sheets that can be loosely layered in a non-sealing manner over injured tissue. Also, pourable substances have been suggested for scavenging TGF-xcex2 from injured tissue sites. These measures, unfortunately, have had only modest success in reducing the formation of post-surgical adhesions at the surgical locations. Therefore, it would be desirable to provide new and improved methods and apparatus that would eliminate of minimize adhesions.
The present invention, generally speaking, provides systems for reducing adhesion formation by reducing, or eliminating, the release of chemical messengers such as TGF-xcex2 at a surgical location in a mammal. More particularly, the systems of the present invention provide, for example, electro-surgical instruments for use following abdominal surgery for substantially immediately sealing off the edges of surgically-made punctures or incisions in the peritoneum to, thereby, limit the release of factors such as the growth factor TGF-xcex2 following injury.
Generally speaking, the present invention provides a system for treating the edges of surgical incisions, or perforations, of the peritoneum for reducing the incidence of post-surgical adhesions, where the system includes means that are applied to, or act upon, the edges of the incised or perforated tissue of the peritoneum for sufficiently sealing the incised or perforated tissue to substantially reduce the incidence of post-surgical adhesions at the surgical site.
In one particular embodiment, the invention provides a system for sufficiently sealing the edges of incised or perforated tissue of the peritoneum to substantially reduce the incidence of post-surgical adhesions at the surgical site by heating the lymphatic tissue sufficiently to inhibit (i.e., reduce) the release of various factors and consequently inhibit or minimize the release of adhesion-producing substances such as growth factors. In one preferred practice with this embodiment, heat is produced by controlled radio-frequency energy for application to the edge of an incised or surgically injured peritoneal or pleural tissue. In practice, a wide variety of electromagnetic energy sources such as microwave, infrared, ultraviolet, optical (e.g., laser), and mechanical energy (e.g., ultrasound), could be used to generate heat.
In another particular embodiment, the invention provides a system for sufficiently sealing the edges of incised or perforated tissue of peritoneum to substantially reduce the incidence of post-surgical adhesions at the surgical site by cooling the edge of an incised or surgically injured peritoneal or pleural tissue sufficiently to inhibit (i.e. reduce) the release of adhesion-producing substances such as growth factors and consequently inhibit or minimize adhesion formation. In practice of this embodiment, cooling is accomplished by applying a low-boiling point liquid substance such as liquid nitrogen, Freon(trademark) or the like to the edges of incised or perforated tissue.
In another particular embodiment, the invention provides a system for sufficiently sealing the edges of incised or perforated tissue of peritoneum to substantially reduce the incidence of post-surgical adhesions at the surgical site by applying a sealing substance at the site of injury. The sealing substance inhibits (i.e., reduces) the release of adhesion-producing substances such as growth factors and consequently inhibit or minimize adhesion formation. In practice of this embodiment, the sealing substance can be a biocompatable barrier material such as a cyanoacrylate liquid, or the like, that is applied to the edges of incised or perforated tissue. Other bio-compatible synthetic sealing materials could be polyvinyl resins, polylactate glycolides, polycaprolactones, poly oxyethylenes, and other such materials. One could also use biological materials such as proteins like collagen, gelatin, elastin, albumins, and the like, or mixtures thereof.